The effect of helicobacter pylori eradication therapy on gastric antral myoelectrical activity and gastric emptying in patients with non-ulcer dyspepsia

Helicobacter pylori eradication improves motor fluctuations in advanced Parkinson's disease patients: A prospective cohort study (HP-PD trial)

BACKGROUND

Helicobacter pylori (HP) is a bacterium associated with many gastrointestinal (GI) diseases and has shown a high prevalence in Parkinson's disease (PD). As HP-associated GI dysfunction could affect L-dopa (levodopa) absorption, HP eradication might improve the clinical response and decrease motor fluctuations.

METHODS

A prospective cohort study was conducted on the clinical symptoms of PD patients with motor fluctuations. The 13C-urea breath test was used to diagnose a current HP infection. All patients with HP infection received a 2-week regimen of triple therapy. The changes in the Unified Parkinson's Disease Rating Scale (UPDRS) motor score, L-dopa onset time, wearing-off symptoms, mean daily on-off time, GI symptom scores, and quality of life score were measured at baseline and at a 6-week follow-up.

RESULTS

A total of 163 PD patients were assessed, of whom 40 were enrolled. Fifty-five percent of the enrolled patients (22/40) had a current HP infection, whereas HP eradication was identified in 17 of 22 (77.3%) patients who received eradication therapy. Patients with HP eradication showed a significant decrease in daily 'off' time (4.0 vs. 4.7 h, p = 0.040) and an increase in daily 'on' time (11.8 vs. 10.9 h, p = 0.009). Total wearing-off score (4.4 vs. 6.0, p = 0.001) and the GI symptom score (8.1 vs. 12.8, p = 0.007) were significantly improved. There was no significant improvement in L-dopa onset time, UPDRS motor score, or quality of life score.

CONCLUSIONS

HP eradication leads to significant clinical improvement in the symptoms of PD. Eradication of HP not only increases the total daily 'on' time but also decreases wearing-off symptoms and improves GI symptoms.

Role of Helicobacters in Neuropsychiatric Disease: A Systematic Review in Idiopathic Parkinsonism

Interest in an aetiopathogenic role for Helicobacter in neuropsychiatric diseases started with idiopathic parkinsonism (IP), where the cardinal signs can be assessed objectively. This systematic review, using an EMBASE database search, addresses Oxford Centre for Evidence-Based Medicine based questions on the inter-relationship of Helicobacter and IP, the benefits of eradicating Helicobacter in IP and the outcome of not treating. The search strategy was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines: 21 of 204 articles met the inclusion criteria. The results show that the assumption that any benefit of Helicobacter eradication results from improved levodopa bioavailability is unjustified. The inter-relationship between Helicobacter and IP is well-established. H. pylori virulence markers (associated with autoimmunity and immune tolerance) influence the risk, severity and progression of IP. The birth cohort effect for virulence marker antibodies, seen in controls, is obliterated in IP, suggesting causality. Successful H. pylori eradication in IP is disease-modifying (even in anti-parkinsonian treatment-naïve patients) but not preventive. Hypokinesia regresses with eradication and overall motor severity lessens. Eradication may influence gastrointestinal microbiota adversely, unlocking the next stage in the natural history, the development of rigidity. Failed eradication worsens hypokinesia, as does the presence/persistence of H. pylori at molecular level only. Adequate prognostic assessment of the consequences of not treating Helicobacter, for IP, is prevented by a short follow-up. We conclude that Helicobacter is a pathophysiological driver of IP.

Review article: treatment options for functional dyspepsia

BACKGROUND

Functional dyspepsia, consisting of epigastric pain syndrome and postprandial distress syndrome, is a prevalent functional gastrointestinal disorder. To date, only limited treatment options are available and conflicting results in terms of efficacy have been reported. Consequently, nonpharmacological treatment options are increasingly being explored for functional dyspepsia.

AIM

To provide an overview of current pharmacological and nonpharmacological treatment options for functional dyspepsia.

METHODS

A literature search was conducted on Pubmed and other sources to identify relevant studies.

RESULTS

Acid suppressive therapy reduced symptoms in 30%-70% of the patients, with higher benefit in epigastric pain syndrome and superior effectiveness for proton pump inhibitors compared to H₂ -antagonists. Prokinetic agents, primarily used to treat postprandial distress syndrome, showed variable efficiency: 59%-81% responder rate for dopamine receptor antagonists, 32%-91% for serotonin-4-receptor agonists and 31%-80% for muscarinic receptor antagonists. H Pylori eradication, recommended in infected patients, was effective in 24%-82%. Refractory symptoms are addressed with neuromodulators. However, their efficacy in functional dyspepsia remains incompletely elucidated, available data showing symptom reduction in 27%-71% of the patients. Regarding herbal agents, peppermint oil reduced symptoms in 66%-91%, rikkunshito in 29%-34% and iberogast in 20%-95%. Lastly, acupuncture, cognitive behavioural therapy and hypnotherapy may help to provide symptom control, but research on their efficacy remains sparse.

CONCLUSIONS

None of the available therapies is effective in the majority of patients without being associated with major side effects. Developing new treatment options is challenging due to the heterogeneity of functional dyspepsia, the lack of readily identified target mechanisms and the poor association between pathophysiological disturbances and symptoms.

All disease begins in the gut: Influence of gastrointestinal disorders and surgery on oral drug performance

The term "disease" conjures a plethora of graphic imagery for many, and the use of drugs to combat symptoms and treat underlying pathology is at the core of modern medicine. However, the effects of the various gastrointestinal diseases, infections, co-morbidities and the impact of gastrointestinal surgery on the pharmacokinetic and pharmacodynamic behaviour of drugs have been largely overlooked. The better elucidation of disease pathology and the role of underlying cellular and molecular mechanisms have increased our knowledge as far as diagnoses and prognoses are concerned. In addition, the recent advances in our understanding of the intestinal microbiome have linked the composition and function of gut microbiota to disease predisposition and development. This knowledge, however, applies less so in the context of drug absorption and distribution for orally administered dosage forms. Here, we revisit and re-evaluate the influence of a portfolio of gastrointestinal diseases and surgical effects on the functionality of the gastrointestinal tract, their implications for drug delivery and attempt to uncover significant links for clinical practice.

Drug-gut microbiota interactions: implications for neuropharmacology

The fate and activity of drugs are frequently dictated not only by the host per se but also by the microorganisms present in the gastrointestinal tract. The gut microbiome is known to, both directly and indirectly, affect drug metabolism. More evidence now hints at the effects that drugs can have on the function and composition of the gut microbiome. Both microbiota-mediated alterations in drug metabolism and drug-mediated alterations in the gut microbiome can have beneficial or detrimental effects on the host. Greater insights into the mechanisms driving these reciprocal drug-gut microbiota interactions are needed to guide the development of microbiome-targeted dietary or pharmacological interventions, which may have the potential to enhance drug efficacy or reduce drug side effects. In this review, we explore the relationship between drugs and the gut microbiome, with a specific focus on potential mechanisms underpinning the drug-mediated alterations on the gut microbiome and the potential implications for psychoactive drugs. LINKED ARTICLES: This article is part of a themed section on When Pharmacology Meets the Microbiome: New Targets for Therapeutics? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.24/issuetoc.

Transient receptor potential vanilloid 4 (TRPV4) silencing in Helicobacter pylori-infected human gastric epithelium

BACKGROUND

Helicobacter pylori (HP) infection induces methylation silencing of specific genes in gastric epithelium. Various stimuli activate the nonselective cation channel TRPV4, which is expressed in gastric epithelium where it detects mechanical stimuli and promotes ATP release. As CpG islands in TRPV4 are methylated in HP-infected gastric epithelium, we evaluated HP infection-dependent changes in TRPV4 expression in gastric epithelium.

MATERIALS AND METHODS

Human gastric biopsy samples, a human gastric cancer cell line (AGS), and a normal gastric epithelial cell line (GES-1) were used to detect TRPV4 mRNA and protein expression by RT-PCR and Western blotting, respectively. Ca²⁺ imaging was used to evaluate TRPV4 ion channel activity. TRPV4 methylation status was assessed by methylation-specific PCR (MSP). ATP release was measured by a luciferin-luciferase assay.

RESULTS

TRPV4 mRNA and protein were detected in human gastric biopsy samples and in GES-1 cells. MSP and demethylation assays showed TRPV4 methylation silencing in AGS cells. HP coculture directly induced methylation silencing of TRPV4 in GES-1 cells. In human samples, HP infection was associated with TRPV4 methylation silencing that recovered after HP eradication in a time-dependent manner.

CONCLUSION

HP infection-dependent DNA methylation suppressed TRPV4 expression in human gastric epithelia, suggesting that TRPV4 methylation may be involved in HP-associated dyspepsia.

Helicobacter pylori infection and drugs malabsorption

Drug absorption represents an important factor affecting the efficacy of oral drug treatment. Gastric secretion and motility seem to be critical for drug absorption. A causal relationship between impaired absorption of orally administered drugs and Helicobacter pylori (H. pylori) infection has been proposed. Associations have been reported between poor bioavailability of l-thyroxine and l-dopa and H. pylori infection. According to the Maastricht Florence Consensus Report on the management of H. pylori infection, H. pylori treatment improves the bioavailability of both these drugs, whereas the direct clinical benefits to patients still await to be established. Less strong seems the association between H. pylori infection and other drugs malabsorption, such as delavirdine and ketoconazole. The exact mechanisms forming the basis of the relationship between H. pylori infection and impaired drugs absorption and/or bioavailability are not fully elucidated. H. pylori infection may trigger a chronic inflammation of the gastric mucosa, and impaired gastric acid secretion often follows. The reduction of acid secretion closely relates with the wideness and the severity of the damage and may affect drug absorption. This minireview focuses on the evidence of H. pylori infection associated with impaired drug absorption.

Current status of multichannel electrogastrography and examples of its use

Electrogastrography (EGG) is a non-invasive diagnostic motility for recording gastric myoelectrical activity. Gastric myoelectrical activity was first recorded in 1922. Advances in recording equipment enabled widespread use of cutaneous EGG after 1985. Later, introduction of multichannel EGG (M-EGG) enabled measurement of electrical activity transmission. At present, M-EGG findings are used as objective indicators of gastric motility disorders caused by various diseases. EGG measures two categories of gastric electrical activity: electrical response activity, or spike potentials; and electrical control activity, or slow waves. The appearance of abnormal rhythmic electrical activity is indicative of abnormalities in gastric motility. The normal frequency range of gastric electrical activity (normogastria) is around 3 cycles per min. Multiple EGG parameters assist in the assessment of gastric myoelectrical activity, and significant correlations between EGG and other gastric motility tests have been demonstrated in many studies. In Japan, however, EGG remains in the exploratory stage, and its clinical use is limited. There are large variations in procedures and systems used in previous studies, thus there is a need for standardization of EGG procedures and technical terminology. Here, we outline the current status of EGG and report the M-EGG procedures used in our department in addition to our M-EGG findings.

The abstract of this manuscript was presented during an educational seminar titled "Current status of gastrointestinal motility tests and keys for immediate implementation" at the 54th Annual Meeting of the Japan Society of Smooth Muscle Research

Helicobacter pylori infection in functional dyspepsia

Functional dyspepsia is the most common reason for patients to experience chronic epigastric pain or discomfort. The causes of functional dyspepsia are multifactorial but Helicobacter pylori infection is one likely candidate. Infection with this bacterial pathogen clearly results in chronic mucosal inflammation in the stomach and duodenum, which, in turn, might lead to abnormalities in gastroduodenal motility and sensitivity. Chronic gastritis might also affect a variety of endocrine functions of the stomach including the production of the gastrointestinal hormones and neurotransmitters somatostatin, gastrin and ghrelin. Although these abnormalities might generate symptoms in some patients with functional dyspepsia, the clinical evidence needs to be critically evaluated before this hypothesis can be confirmed. A Cochrane review reported that eradication of H. pylori in these patients had a small but statistically significant long-term effect on symptom relief when compared with placebo, lasting at least 12 months after 1 week of eradication therapy. The efficacy of eradication therapy was seen in all symptom subtypes of functional dyspepsia, but was more marked in Asian than Western patients. This evidence has led to alterations in most of the major guidelines throughout the world, which now recommend H. pylori eradication in patients with functional dyspepsia if they test positive for this bacterium.

Gastroparesis: concepts, controversies, and challenges

Patients with gastroparesis often present a challenge to the treating physician. Postprandial symptoms with nausea and vomiting may not only lead to nutritional and metabolic consequences, but also cause significant disruptions to social activities that often center around food. While the definition of gastroparesis focuses on impaired gastric emptying, treatment options that affect gastric function are limited and often disappointing. The female predominance, the mostly idiopathic nature of the illness with a common history of abuse, and coexisting anxiety or depression show parallels with other functional disorders of the gastrointestinal tract. These parallels provided the rationale for some initial studies investigating alternative therapies that target the brain rather than the stomach. This emerging shift in medical therapy comes at a time when clinical studies suggest that gastric electrical stimulation may exert its effects by modulating visceral sensory processing rather than altering gastric motility. Physiologic and detailed anatomic investigations also support a more complex picture with different disease mechanisms, ranging from impaired accommodation to apparent visceral hypersensitivity or decreased interstitial cells of Cajal to inflammatory infiltration of myenteric ganglia. Delayed gastric emptying remains the endophenotype defining gastroparesis. However, our treatment options go beyond prokinetics and may allow us to improve the quality of life of affected individuals.

Epidemiology of uninvestigated and functional dyspepsia in Asia: facts and fiction

Dyspepsia is a syndrome consisting of epigastric pain, burning, fullness, discomfort, early satiety, nausea, vomiting and belching. Functional dyspepsia (FD) is diagnosed if upper gastrointestinal endoscopy does not show structural abnormality explaining these symptoms. 8%-30% and 8%-23% of Asian people suffer from of uninvestigated dyspepsia and FD, respectively. Most patients with uninvestigated dyspepsia are found to have FD. Patients with FD are usually young and there is no predilection to any gender. Overlap of FD with other functional bowel diseases such as irritable bowel syndrome and gastroesophageal reflux disease is common in Asia. Cultural difference in reporting of symptoms of dyspepsia is well-known. Moreover, dietary factors, socio-cultural and psychological issues, gastrointestinal infection including that caused by Helicobacter pylori, frequency of organic diseases such as peptic ulcer and gastric cancer responsible for dyspeptic symptoms in the study population may also influence epidemiology of dyspepsia. There is considerable heterogeneity in the above issues among different Asian countries. More studies on epidemiology of FD are needed in Asia.

Early satiety is the only patient-reported symptom associated with delayed gastric emptying, as assessed by breath-test

Background/Aims

To evaluate associations between delayed gastric emptying (GE) assessed by the octanoic acid breath test and upper gastrointestinal (GI) symptoms.

Methods

A historical, prospective study included 111 consecutive symptomatic adults referred for a GE breath test because of upper abdominal symptoms suggestive of delayed GE. Exclusion criteria included underlying organic disease associated with delayed GE. Patients completed a symptom questionnaire and underwent a GE octanoic breath test. Patients with delayed GE were compared with those with normal results, for upper GI symptoms.

Results

Early satiety was the only symptom significantly associated with delayed GE. It was observed in 52% of subjects with delayed GE compared to 33% patients with no evidence of delayed GE (P = 0.005). This association was seen for all degrees of severity of delayed GE. Patients with early satiety had a t_1/2 of 153.9 ± 84.6 minutes compared to 110.9 ± 47.6 minutes in subjects without it (P = 0.002). In a logistic regression model, early satiety was significantly associated with delayed GE (OR, 2.29; 95% CI, 1.01-5.18; P = 0.048).

Conclusions

Early satiety is the only patient-reported GI symptom associated with delayed GE. The utility of GE tests as a clinical diagnostic tool in the work-up of dyspeptic symptoms may be overrated.

Predictors of gastric myoelectrical activity in type 2 diabetes mellitus

BACKGROUND

Previous studies have clearly demonstrated the delayed gastric emptying of solid meals in diabetics, whereas their gastric myoelectrical activity, which primarily determines gastric motility, has not yet been fully confirmed.

GOALS

This study aimed to clarify the characteristics and potential predictors of gastric myoelectrical activity in type 2 diabetics.

STUDY

Twenty-eight diabetics and 18 healthy controls participated. Duodenal biopsy sample was used for reverse transcription-polymerase chain reaction to evaluate cholecystokinin and motilin mRNA contents. Electrogastrography was performed before and after the test meal, and was assessed in terms of dominant frequency; dominant frequency instability coefficient; and the percentage of bradygastria, normogastria, and tachygastria.

RESULTS

Over the entire recording period, dominant frequency was significantly lower, and dominant frequency instability coefficient and the percentage of bradygastria were significantly higher in diabetics than in controls. In diabetics, the multiple regression analysis demonstrated that dominant frequency instability coefficient and the percentage of tachygastria in the fasting period were dependent on fasting plasma glucose level and HbA1c, respectively. Moreover, dominant frequency over the entire period and the postprandial percentage of bradygastria were significantly associated with body mass index; the fasting percentage of bradygastria and postprandial dominant frequency instability coefficient were associated with fasting serum leptin level; the postprandial percentage of bradygastria was also associated with cholecystokinin mRNA content.

CONCLUSIONS

Gastric myoelectrical activity in type 2 diabetics is impaired on dominant frequency, dominant frequency instability coefficient, and the percentage of bradygastria and predicted by body mass index, fasting serum leptin level, and cholecystokinin mRNA content besides the glycemic status.

Effects of repeated restraint stress on gastric motility in rats

In our daily life, individuals encounter with various types of stress. Accumulation of daily life stress (chronic stress) often causes gastrointestinal symptoms and functional gastrointestinal diseases. Although some can adapt toward chronic stress, the adaptation mechanism against chronic stress remains unknown. Although acute stress delays gastric emptying and alters upper gastrointestinal motility, effects of chronic stress on gastric motility still remain unclear. We investigated the effects of acute (single stress) and chronic (repeated stress for 5 consecutive days) stress on solid gastric emptying and interdigestive gastroduodenal contractions in rats. It is well established that acute restraint stress inhibits solid gastric emptying via central corticotropin-releasing factor (CRF). To investigate whether the sensitivity to CRF is altered following chronic stress, CRF was administered intracisternally. Ghrelin is involved in regulating gastric emptying and upper gastrointestinal motility in rodents. The changes in plasma active ghrelin levels and mRNA expression in the stomach were studied following chronic stress. To evaluate the effects of chronic stress on the hypothalamus-pituitary-adrenal (HPA) axis, plasma corticosterone levels were also measured. Delayed gastric emptying observed in acute stress was completely restored following chronic stress. Acute stress abolished gastric phase III-like contractions, without affecting duodenal phase III-like contractions in the interdigestive state. Impaired gastric phase III-like contractions were also restored following chronic stress. Plasma ghrelin levels and ghrelin mRNA expression were increased significantly after chronic stress. Intracisternal injection of CRF delayed gastric emptying and impaired gastric motility in rats who received chronic stress. Plasma corticosterone concentrations were no more elevated following chronic stress. The restored gastric emptying following chronic stress was antagonized by the administration of ghrelin receptor antagonists. The adaptation mechanism may involve upregulation of ghrelin expression and attenuation of the HPA axis. In contrast, the sensitivity to central CRF remained unaltered following chronic stress in rats.

Systematic review: Helicobacter pylori infection and impaired drug absorption

BACKGROUND

Impaired acid secretion may affect drug absorption and may be consequent to corporal Helicobacter pylori-gastritis, which may affect the absorption of orally administered drugs.

AIM

To focus on the evidence of impaired drug absorption associated with H. pylori infection.

METHODS

Data sources were the systematic search of MEDLINE/EMBASE/SCOPUS databases (1980-April 2008) for English articles using the keywords: drug malabsorption/absorption, stomach, Helicobacter pylori, gastritis, gastric acid, gastric pH, hypochlorhydria, gastric hypoacidity. Study selection was made from 2099 retrieved articles, five studies were identified. Data were extracted from selected papers, investigated drugs, study type, main features of subjects, study design, intervention type and results were extracted.

RESULTS

In all, five studies investigated impaired absorption of l-dopa, thyroxine and delavirdine in H. pylori infection. Eradication treatment led to 21-54% increase in l-dopa in Parkinson's disease. Thyroxine requirement was higher in hypochlorhydric goitre with H. pylori-gastritis and thyrotropin levels decreased by 94% after treatment. In H. pylori- and HIV-positive hypochlorhydric subjects, delavirdine absorption increased by 57% with orange juice administration and by 150% after eradication.

CONCLUSIONS

A plausible mechanism of impaired drug absorption is decreased acid secretion in H. pylori-gastritis patients. Helicobacter pylori infection and hypochlorhydria should be considered in prescribing drugs the absorption of which is potentially affected by intragastric pH.

Role of gut-brain axis in persistent abnormal feeding behavior in mice following eradication of Helicobacter pylori infection

Bacterial infection can trigger the development of functional GI disease. Here, we investigate the role of the gut-brain axis in gastric dysfunction during and after chronic H. pylori infection. Control and chronically H. pylori-infected Balb/c mice were studied before and 2 mo after bacterial eradication. Gastric motility and emptying were investigated using videofluoroscopy image analysis. Gastric mechanical viscerosensitivity was assessed by cardioautonomic responses to distension. Feeding patterns were recorded by a computer-assisted system. Plasma leptin, ghrelin, and CCK levels were measured using ELISA. IL-1beta, TNF-alpha, proopiomelanocortin (POMC), and neuropeptide Y mRNAs were assessed by in situ hybridizations on frozen brain sections. Gastric inflammation was assessed by histology and immunohistochemistry. As shown previously, H. pylori-infected mice ate more frequently than controls but consumed less food per bout, maintaining normal body weight. Abnormal feeding behavior was accompanied by elevated plasma ghrelin and postprandial CCK, higher TNF-alpha (median eminence), and lower POMC (arcuate nucleus) mRNA. Infected mice displayed delayed gastric emptying and visceral hypersensitivity. Eradication therapy normalized gastric emptying and improved gastric sensitivity but had no effect on eating behavior. This was accompanied by persistently increased TNF-alpha in the brain and gastric CD3(+) T-cell counts. In conclusion, chronic H. pylori infection in mice alters gastric emptying and mechanosensitivity, which improve after bacterial eradication. A feeding pattern reminiscent of early satiety persists after H. pylori eradication and is accompanied by increased TNF-alpha in the brain. The results support a role for altered gut-brain pathways in the maintenance of postinfective gut dysfunction.

Antral inflammatory cells, gastric emptying, and electrogastrography in pediatric functional dyspepsia

The aims of the current study were to determine the activation states of antral eosinophils and mast cells and to evaluate the interactions of antral inflammatory cells with gastric emptying and electrogastrography (EGG) in 30 pediatric patients with functional dyspepsia. Eosinophil degranulation was moderate in 42% and extensive in 54% of patients. Mast cell degranulation was > 50% in 81% of patients. Elevated mast cell density was associated with slower one hour gastric emptying and increased preprandial dysrhythmia. Mast cell density correlated with the preprandial percentage tachygastria. CD3+ cell density correlated with the preprandial percentage tachygastria also, but only in patients with increased eosinophil density. In conclusion, antral eosinophils and mast cells are significantly activated in pediatric functional dyspepsia. Mast cell density is associated with delayed gastric emptying and preprandial dysrhythmia, suggesting that there may be an interaction between antral inflammation and gastric electromechanical dysfunction in the pathophysiology of pediatric functional dyspepsia.

Symptoms, endoscopic findings and histology predicting symptomatic benefit of Helicobacter pylori eradication

OBJECTIVE

To analyse factors predicting changes in dyspeptic symptoms after Helicobacter pylori eradication.

MATERIAL AND METHODS

Of a total of 342 patients referred for upper gastrointestinal endoscopy at 23 centres in various parts of Finland, those tested positive for the rapid urease test were recruited in the study. Clinical and demographic data and data on dyspeptic symptoms (Gastrointestinal Symptoms Rating Scale) were collected via a structured questionnaire before and a year after the eradication therapy. Gastric biopsies were analysed according to the updated Sydney system.

RESULTS

A total of 216 H. pylori-positive patients treated successfully with eradication therapy had complete data to be analysed. After the therapy, dyspeptic symptoms decreased by 29-32%. In a univariate analysis, it was found that duodenal ulcer, female gender, gastric antral neutrophilic inflammation, smoking and age from 50 to 59 years enhanced symptom improvement whereas atrophy in the gastric body reduced it. In a multivariate analysis, duodenal ulcer (odds ratio (OR) 3.2, 95% CI 1.3-7.8) and age from 50 to 59 years (OR 2.2; 95% CI 1.2-3.9) and antral neutrophilic inflammation (OR 1.9, 95% CI 1.1-3.3) were better predictors of symptomatic response.

CONCLUSION

The symptomatic benefit from H. pylori eradication therapy was greatest among duodenal ulcer patients.

Multichannel electrogastrography under a magnifying glass--an in-depth study on reproducibility of fed state electrogastrograms

We checked on reproducibility of parameters of a multichannel electrogastrogram in adults after intake of typical, applied in electrogastrography, test meals. Recordings of multichannel electrogastrograms were accomplished in four blocks comprising 18 subjects (nine healthy volunteers and nine patients with functional GI disorders) each. Every subject had two examinations taken 1-2 days apart, and a third one was accomplished at least 2 weeks before or after the two other sessions. The registration involved a 30-min fasted and a 2-h postprandial period after one of the meal stimuli tested within a given block: 400 mL water, 400 g yoghurt (378 kcal), a scrambled eggs sandwich (370 kcal), a pancake (355 kcal). From among the parameters reflecting the propagation of the gastric slow waves, the average percentage of slow wave coupling (APSWC) exhibited a good (coefficient of variation for paired examinations CV(p) < or = 10%) to moderate (10 < CV(p) < or = 30%) reproducibility. On the other hand, the reproducibility of the maximum dominant frequency difference and the spatial dominant power difference was found to be unsatisfactory. The reproducibility of the multichannel electrogastrographic parameters did not differ between healthy volunteers and patients with functional GI disorders. Gender or the kind of a test meal did not affect the reproducibility of the electrogastrographic parameters either. The medium-term reproducibility was not any worse than the short-term one. From among the parameters of a multichannel electrogastrogram intended to quantify the propagation of slow waves, only the APSWC offers a reproducibility potentially good enough for clinical applications.

Effect of chronic stress on gastric emptying and plasma ghrelin levels in rats

Chronic stress is associated with gastrointestinal functional diseases. Although the pathophysiology seems to be associated with gastrointestinal motility, their mechanisms remain unclear. We investigated gastric emptying and chemical mediators under conditions of continuous stress, which were produced using 8-week-old male Wistar rats kept in a cage filled with water to 2 cm height for 5 days. We examined gastric emptying by the phenol red method and chemical mediators at 4, 8, and 24 h and 3 and 5 days after initiation of stress restraint. Plasma ACTH level was significantly higher in the stress throughout the period of measurement. Continuous stress delayed gastric emptying until 24 h: peak delay was observed at 8 h, whereas gastric emptying was accelerated on days 3 and 5. Plasma noradrenalin level was significantly elevated at every time point until 24 h. Guanethidine pretreatment eliminated the delay in gastric emptying at 8 h. Active ghrelin was significantly increased on days 3 and 5 after peak (at 24 h) plasma total and desacyl ghrelin in the stress group. Number of ghrelin-immunoreactive cells and level of preproghrelin mRNA expression in the gastric body increased in parallel with plasma active ghrelin level. Pretreatment with growth hormone secretagogue receptor antagonist at 5 days partially inhibited the stress-induced acceleration of gastric emptying. Delayed gastric emptying at acute phase of continuous stress was mediated via sympathetic pathway, while acceleration at chronic phase was mediated via increased active ghrelin release from the stomach.

Rabeprazole delays gastric emptying of a nutrient liquid

BACKGROUND

It is generally considered that gastric acid suppression delays gastric emptying of solid meals because gastric hypoacidity impairs peptic digestion and antral triturition. Rabeprazole is one of the most potent acid suppressants. We conducted this cross-over study to investigate if rabeprazole delays gastric emptying of liquid nutrients, for which peptic digestion is unnecessary.

METHODS

On two randomized occasions, 13 healthy male volunteers underwent the (13)C-acetate breath test following ingestion of a 300 kcal-liquid meal. On one occasion, they had received 20 mg rabeprazole for the preceding 2 days and 1 h before the test. On another, they took no pretreatment. Based on 4 h breath samples, the half (13)CO(2) excretion time (t(1/2b)) and the time of maximal excretion (t(max)) were calculated as overall measures of gastric emptying. In addition, time profiles of gastric emptying were generated using the Wagner-Nelson analytical method, which creates the gastric emptying curve as accurately as the scintigraphy.

RESULTS

Rabeprazole significantly prolonged t(max) but unchanged t(1/2b). The gastric emptying profiles showed that rabeprazole evoked a segmental slowing of gastric emptying during 0.5-1.25 h of post-meal ingestion.

CONCLUSIONS

Rabeprazole suppresses gastric emptying of a liquid nutrient 0.5 h after meal ingestion. We have speculated that: (i) rabeprazole delays gastric emptying via a mechanism other than acid-pepsin maldigestion; and (ii) rabeprazole may intensify the post-gastric feedback regulation system (>0.5 h of post-meal).

Gastric emptying in diabetic patients by the (13)C-octanoic acid breath test: role of insulin in gastric motility

BACKGROUND

Impairment of gastric emptying is well recognized in patients with diabetes mellitus (DM), especially long-standing insulin-dependent diabetes mellitus (IDDM). The aim of this study was to evaluate the cause of delayed gastric emptying in DM patients.

METHODS

In 16 controls, 16 non-insulin-dependent diabetes mellitus (NIDDM) patients and 23 IDDM patients, gastric emptying was studied using the (13)C octanoic acid breath test. Breath samples were taken before a test meal labeled with 100 mg of (13)C octanoic acid, and at 15-min intervals over a 300-min period postprandially.

RESULTS

In all DM patients, the gastric emptying coefficient was lower than that in the controls (P < 0.05), and lag time and half-emptying time were significantly longer (P < 0.05). Both NIDDM and IDDM patients showed delayed (13)CO(2) excretion compared with the controls, but IDDM patients showed more delayed gastric emptying than NIDDM patients (P < 0.05). There were no significant differences in sex, HbA1c level, or the rate of neuropathy between the two groups.

CONCLUSIONS

IDDM patients showed delayed gastric emptying compared with NIDDM patients, and the (13)C octanoic acid breath test is useful for evaluating DM patients with delayed gastric emptying.

Helicobacter pylori eradication versus prokinetics in the treatment of functional dyspepsia: a randomized, double-blind study

BACKGROUND

This randomized, double-blind study compared the efficacy of Helicobacter pylori eradication against prokinetics in H. pylori-infected functional dyspepsia patients.

METHODS

Patients with moderately severe or severe dyspepsia fulfilling the Rome II criteria were randomized to either H. pylori eradication for 1 week and 6 weeks of placebo prokinetics or 6 weeks of prokinetics and placebo H. pylori eradication in the first week. Symptoms were assessed at baseline and at 6 and 12 months using the Glasgow Dyspepsia Severity Score (GDSS). Global response to treatment was assessed at 12 months.

RESULTS

Altogether 130 patients were enrolled (H. pylori eradication, 71; prokinetics, 59). The mean baseline GDSS was 9.3 for the H. pylori eradication group and 8.9 for the prokinetic group. At 6 months, the score was 3.6 and 4.1, respectively, and it remained at 3.5 and 3.8, respectively, at 12 months. With H. pylori eradication, 31.0% had complete symptom resolution (GDSS 0 or 1) at 12 months compared with 23.7% with prokinetics (a nonsignificant difference). At 12 months, global symptomatic improvement was seen in 62.0% of the H. pylori eradication group compared with 67.8% of the prokinetics group.

CONCLUSIONS

Both H. pylori eradication and prokinetic therapy resulted in symptom improvement in two-thirds of dyspeptic patients at 1 year. More patients tended to achieve complete symptom relief with H. pylori eradication.

Effects of Helicobacter pylori eradication therapy on gastric emptying measured using the 13C-octanoic acid breath test and the acetaminophen method

BACKGROUND

The relationship between Helicobacter pylori eradication and gastric emptying has been reported; however, the effect of eradication therapy on gastric emptying is still unclear. This study evaluated the relationship between three gastric emptying techniques, the scintigraphic technique, the 13C-octanoic acid breath test, and the acetaminophen method, measured simultaneously, and the effect of H. pylori eradication therapy on gastric emptying and abdominal symptoms in patients with functional dyspepsia who were H. pylori positive.

METHODS

Fifty-three consecutive patients with positive H. pylori infection were enrolled in this study. In the first 14 patients, gastric emptying was measured using the three gastric emptying techniques. In 42 patients cured of H. pylori infection, the 13C-octanoic acid breath test and the acetaminophen method were performed before and 3 months after eradication.

RESULTS

Significant correlations were found between the scintigraphic technique, the 13C-octanoic acid breath test, and the acetaminophen method. Gastric emptying determined by the 13C-octanoic acid breath test and the acetaminophen method was not changed after eradication, on average. In 14 (33.3%) patients a decrease in symptom score after eradication was observed. In four (9.5%) patients, accelerated gastric emptying after eradication may have led to a reduction in the abdominal symptoms.

CONCLUSIONS

The 13C-octanoic acid breath test and the acetaminophen method are appropriate for investigating gastric emptying. A causal relationship between improvement of symptoms and accelerated gastric emptying was not found, and the efficacy of H. pylori eradication therapy in patients with functional dyspepsia was minimally exhibited.

Electrogastrography: basic knowledge, recording, processing and its clinical applications

The slow wave (SW) of the gastrointestinal (GI) tract mainly functions to trigger the onset of spike to elicit smooth muscle contraction, which provides the essential power of motility. Smooth muscle myogenic control activity or SW is believed to originate in the interstitial cells of Cajal (ICC). The electrical coupling promotes interaction between muscle cells, and ICC additionally contribute to SW rhythmicity. Stomach SW originates in the proximal body showing the continuous rhythmic change in the membrane potential and propagates normally to the distal antrum with a regular rhythm of approximately 3 c.p.m. A technique using electrodes positioned on the abdominal skin to pick up stomach rhythmic SW refers to electrogastrography (EGG). The stomach SW amplitude is very weak, while many visceral organs also produce rhythmic electricities, for example heartbeat, respiration, other organs of the GI tract and even body movements. Thus noise other than SW should be filtered out during the recording, while motion artifacts are visually examined and deleted. Finally, the best signal among all recordings is selected to compute EGG parameters based on spectral analysis. The latter is done not only to tranform frequency domain to time domain but also to provide information of time variability in frequency. Obtained EGG parameters include dominant frequency/power, % normal rhythm, % bradygastria, % tachygastria, instability coefficient and power ratio. Clinical experience in EGG has been markedly accumulated since its rapid evolution. In contrast, lack of standardized methodology in terms of electrode positions, recording periods, test meals, analytic software and normal reference values makes the significance of EGG recording controversial. Unlike imaging or manometrical studies, stomach motility disorders are not diagnosed based only on abnormal EGG parameters. Limitations of EGG recording, processing, computation, acceptable normal parameters, technique and reading should be known to conduct subjective assessments when EGG is used to resolve stomach dysfunction. Understanding basic SW physiology, recording methodology and indications may open EGG as a new domain to approach the stomach motor dysfunction.

Helicobacter pylori active infection in patients with acute coronary heart disease

OBJECTIVES

To evaluate the possible role of the active Helicobacter pylori infection as a trigger factor in acute coronary heart disease (CHD).

METHODS

Forty patients with acute coronary syndromes, 40 patients with infections other than H. pylori (control group A) and 40 healthy subjects (control group B), pair matched for age, sex and CHD risk factors were studied. In each patient and control subject the presence of H. pylori stool antigen (HpsA) and serum anti-CagA were tested.

RESULTS

Twenty-eight of patients with CHD resulted positive for HpSA compared to 14 patients of control group A and 16 subjects of group B (p=0.00095). No significant difference was found in the anti-CagA positivity among patients with CHD and control groups. Concomitant positivity for anti-CagA and HpSA was found in 13 patients with CHD, four controls of group A and five controls of group B (p=0.017)

CONCLUSIONS

Our findings revealed a higher rate of HpSA positivity and a significantly higher association between HpSA and anti-CagA positivity in patients with acute CHD compared to control groups. These data suggest that active H. pylori infection may play a role as a trigger factor in acute cardiovascular events.

Effects of Helicobacter pylori infection on gastric emptying rate in patients with non-ulcer dyspepsia

AIM: The pathogenesis of delayed gastric emptying in patients with non-ulcer dyspepsia (NUD) remains unclear. We aimed to examine whether gastric emptying rate in NUD patients was associated with Helicobacter pylori (H pylori) infection and whether it was affected by eradication of the infection.

METHODS: Gastric emptying rate of a mixed solid-liquid meal was assessed by the paracetamol absorption method in NUD patients and asymptomatic controls (n = 17). H pylori status was assessed by serology and biopsy urease test. H pylori-positive NUD patients (n = 23) received 10-day triple eradication therapy. H pylori status was re-assessed by biopsy urease test four weeks later, and if eradication was confirmed, gastric emptying rate was re-evaluated.

RESULTS: Thirty-three NUD patients and 17 controls were evaluated. NUD patients had significantly delayed gastric emptying compared with controls. The mean maximum plasma paracetamol concentration divided by body mass (Cmax/BM) was 0.173 and 0.224 mg/L·kg respectively (P = 0.02), the mean area under plasma paracetamol concentration-time curve divided by body mass (AUC/BM) was 18.42 and 24.39 mg·min/L·kg respectively (P = 0.01). Gastric emptying rate did not differ significantly between H pylori-positive and H pylori-negative NUD patients. The mean Cmax/BM was 0.172 and 0.177 mg/L·kg respectively (P = 0.58), the mean AUC/BM was 18.43 and 18.38 mg·min/ L·kg respectively (P = 0.91). Among 14 NUD patients who were initially H pylori-positive, confirmed eradication of the infection did not significantly alter gastric emptying rate. The mean Cmax/BM was 0.171 and 0.160 mg/L·kg before and after Hp eradication, respectively (P = 0.64), the mean AUC/BM was 17.41 and 18.02 mg·min/L·kg before and after eradication, respectively (P = 0.93).

CONCLUSION: Although gastric emptying is delayed in NUD patients compared with controls, gastric emptying rate is not associated with H pylori status nor it is affected by eradication of the infection.

Effect of Helicobacter pylori eradication on gastroesophageal function

BACKGROUND

To elucidate the cause of possible occurrence of reflux esophagitis after Helicobacter pylori eradication, gastric and esophageal function among H. pylori infected Japanese patients were evaluated both before and after eradication therapy.

METHODS

Nine H. pylori-positive patients were studied before and 6 months after successful H. pylori eradication. Studies included gastric emptying, esophageal manometry, gastric and esophageal pH monitoring as well as measuring serum levels of gastrin, pepsinogen I and pepsinogen II.

RESULTS

Helicobacter pylori eradication was associated with a significant change in serum gastrin and pepsinogen levels, consistent with the improvement in mucosal inflammation. There was no significant change in gastric emptying, fasting or postprandial lower esophageal sphincter (LES) pressure, esophageal primary peristaltic contractions, frequency of transient LES relaxation, or gastroesophageal reflux, as assessed by 24 h pH monitoring. The percent time of the gastric pH>4 at night decreased significantly. A 41-year-old male developed erosive gastroesophageal reflux disease (GERD) (Los Angeles Classification Grade A) after eradication. Physiological studies showed he had abnormal esophageal motility prior to H. pylori eradication.

CONCLUSIONS

With the exception of gastric pH at night, most patients did not experience a significant change in gastric or esophageal function after H. pylori eradication. Development of GERD post H. pylori eradication likely reflects an increase in the acidity of the refluxate superimposed on pre-existing abnormalities in gastroesophageal motility.

The impact of B(12) treatment on gastric emptying time in patients with Helicobacter pylori infection

GOALS

The role that vitamin B12 deficiency plays in upper gastrointestinal motor dysfunction is not clear. The aim of this study was to determine whether B12 replacement therapy improves prolonged gastric emptying time in dyspeptic patients with Helicobacter pylori infection.

MATERIALS AND METHODS

The study included 34 H. pylori-positive patients who had low serum levels of B12 but had no other factors associated with altered gastric motility. Each patient underwent a radionuclide gastric emptying study before and after 3 months of B12 replacement therapy. Dyspepsia scores were calculated pretherapy and posttherapy using a semiquantitative scale. A vitamin B12 preparation (1000 microg/d) was given intramuscularly for the first 10 days and then orally for 80 days. H. pylori eradication therapy was delayed for 3 months until the posttreatment radionuclide study was completed.

RESULTS

The mean gastric emptying time before B12 treatment was significantly longer than that after treatment (230 +/- 190 minutes vs. 98 +/- 29 minutes, respectively; P < 0.0001). The mean dyspepsia score was also significantly improved by treatment (5.4 +/- 1.0 vs. 1.2 +/- 1.0, respectively; P < 0.0001).

CONCLUSION

Vitamin B12 deficiency appears to play an important role in the development of gastric dysmotility and its clinical consequences. Replacement therapy will improve gastric emptying in some patients with dyspepsia.

Meta-analysis: the relationship between Helicobacter pylori infection and gastro-oesophageal reflux disease

BACKGROUND

The relationship between Helicobacter pylori infection and its treatment and gastro-oesophageal reflux disease (GERD) is controversial.

AIMS

To establish if H. pylori infection is associated with the presence of GERD and if anti-H. pylori treatment leads to de novo GERD or rebound/exacerbation of GERD.

METHODS

A search of MEDLINE and EMBASE databases was made. Pooled odds ratios (OR) were calculated for de novo GERD and rebound/exacerbated GERD after anti-H. pylori therapy in case-control studies and in therapeutic trials.

RESULTS

Fourteen case-control studies and 10 clinical trials were included. Among case-control studies, pooled OR for the association between H. pylori negative status and GERD was 1.34 [95% confidence interval (CI) 1.15-1.55]. Among therapeutic trials, pooled OR for the association anti-H. pylori therapy - GERD was 2.54 (95% CI 1.92-3.37). The OR for de novo GERD was 3.25 (95% CI 2.09-5.33), and for rebound/exacerbated GERD was 2.39 (95% CI 1.75-3.34). Associations were higher among Asian studies than among North American and European studies.

CONCLUSIONS

This meta-analysis shows significant association between absence of H. pylori infection and GERD symptoms, and a positive association between anti-H. pylori therapy and occurrence of both de novo and rebound/exacerbated GERD. The significance of these associations appears to have been inflated by the effect of single trials and by geographical variations.

Gastric myoelectrical activity in patients with recurrent gastric or duodenal ulcers

The aim of this study was to characterize gastric myoelectrical activity in patients with recurrent gastric ulcer (GU) or duodenal ulcer (DU), and to compare gastric motility between these two groups of patients. Studies were performed in 59 patients with recurrent active peptic-ulcer disease as diagnosed by gastrointestinal endoscopy: 31 patients had a GU and 28 patients had a DU. Gastric myoelectrical activity was evaluated by cutaneous electro-gastrography (EGG). The following EGG parameters were assessed: the percentage of normogastria (regular 2.4-3.6 cpm slow waves); the EGG power ratio; and the occurrence of a postprandial dip (PD), which is the transient decrease in EGG frequency after a meal. In the GU group, no significant change occurred in the percentage of normogastria or in the EGG power ratio observed after treatment with a proton-pump inhibitor. During the healed stage, the occurrence of PD remained unchanged. In contrast, in the DU group, the percentage of normogastria and the EGG power ratio were significantly increased after treatment. Moreover, during the healed stage, the occurrence of PD significantly increased compared with that during the active stage. These findings suggest that abnormal gastric myoelectrical activity plays an important role in the pathophysiology of recurrent GU rather than DU.

Immune-mediated neural dysfunction in a murine model of chronic Helicobacter pylori infection

BACKGROUND & AIMS

Neuromuscular changes producing dysmotility and hyperalgesia may underlie symptom generation in functional gastrointestinal disorders. We investigated whether chronic Helicobacter pylori-induced gastritis causes neuromuscular dysfunction.

METHODS

In vitro muscle contractility and acetylcholine release were evaluated in mice before and after H. pylori eradication. H. pylori colonization and gastritis were graded histologically. Substance P (SP)-, vasoactive intestinal polypeptide (VIP)-, and calcitonin gene-related peptide (CGRP) immunoreactivity (IR) and macrophages were studied by immunohistochemistry.

RESULTS

In Balb/c mice, chronic H. pylori infection did not affect muscle function but augmented antral relaxation after nerve electric field stimulation. Infected mice had lower acetylcholine release by electric field stimulation and had higher density of SP-, CGRP-, and VIP-IR nerves in the stomach and of SP- and CGRP-IR in the spinal cord. Cholinergic nerve dysfunction worsened progressively and was associated with increasing macrophage and mononuclear but not polymorphonuclear infiltrate or bacterial colonization. SCID mice had unchanged acetylcholine release despite high H. pylori colonization and macrophage infiltration. Eradication of H. pylori normalized functional and morphologic abnormalities except for increased density of gastric SP- and CGRP-IR nerves.

CONCLUSIONS

H. pylori infection induces functional and morphologic changes in the gastric neural circuitry that are progressive and lymphocyte dependent, and some persist after H. pylori eradication. The data have direct implications regarding the role of H. pylori infection in functional dyspepsia.

Nonulcer dyspepsia

New definitions of functional disorders in general and nonulcer dyspepsia in particular were published in the period of review. Although the definition of functional dyspepsia as persistent or recurrent unexplained upper abdominal pain or discomfort stayed essentially the same, new definitions of dyspepsia subgroups were introduced based on the predominant symptom; a reflux-like dyspepsia subgroup was not supported. It is hoped that these criteria, derived by a consensus among international experts in the field, will improve the reliability and the interpretability of future epidemiologic and interventional studies. A wide range of studies dealt with the role of putative etiological factors in functional bowel disorders including Helicobacter pylori, altered visceral sensation, or upper intestinal motility. Although eradication of H. pylori does not seem to relieve dyspepsia over placebo in recent studies of nonulcer dyspepsia, eradication of H. pylori has generally been advised because of suspected beneficial long-term effects (eg, treatment of misdiagnosed ulcer disease) that probably overweigh the potential risks.

Theoretical and experimental approaches for studying factors defining the Helicobacter pylori-host relationship

Mathematical modeling has helped develop hypotheses about the role of microbial and host parameters in the initial and subsequent phases of Helicobacter pylori colonization. Transgenic mice have been used to test the hypothesis that the outcome of colonization is influenced by whether bacteria can adhere to available epithelial cell receptors. Complementary use of modeling and experimental approaches should facilitate studies of H. pylori pathogenesis.